64results about How to "Improve cycle retention" patented technology

The invention provides a lithium ion battery cathode material and a preparation method thereof. The method comprises: taking a lithium source, a cobalt source and a compound with doped elements as raw materials, respectively preparing two kinds of bulk phase doped lithium cobalt oxide precursors of median grain diameters (namely D50 grain diameters), carrying out surface doped treatment to the two kinds of lithium cobalt oxide semi-finished products, finally mixing the two kinds of lithium cobalt oxide semi-finished products, carrying out surface coating, and finally preparing the high voltage and high density lithium ion battery cathode material. The prepared lithium ion battery cathode material is featured by good electrical property, specifically high capacity, high cycle retention rate, low thermal expansion coefficient and high compaction density.

In a positive electrode active material for a magnesium secondary battery and a magnesium secondary battery using it, there is contained a powder particle containing a crystal phase having a structure formed with aggregation of a plurality of crystallites, and amorphous phases formed between the crystallites themselves; the amorphous phases contain at least one kind of a metal oxide selected from a vanadium oxide, an iron oxide, a manganese oxide, a nickel oxide and a cobalt oxide; and the crystal phase and the amorphous phases use the positive electrode active material enabling to store and release magnesium ions.

The invention relates to a silicon-containing lithium ion battery with high energy density. The lithium ion battery comprises a positive electrode, a silicon-containing negative electrode, a fluorine-containing electrolyte, a diaphragm, electrode lugs and a packaging material. The silicon-containing negative electrode takes a silicon-based material as a whole or a part of electrochemical active substances. The electrolyte contains lithium salt, a non-aqueous organic solvent capable of dissolving the lithium salt, an SEI film-forming additive and hydrofluoroether. The solubility of the lithiumsalt in the non-aqueous organic solvent capable of dissolving the lithium salt is higher than 2 mol/L. The solubility of the lithium salt in the hydrofluoroether is lower than 0.3 mol/L, wherein the non-aqueous organic solvent capable of dissolving the lithium salt is mutually dissolved with the hydrofluoroether, the non-aqueous organic solvent capable of dissolving the lithium salt and the liquidSEI film-forming additive are mutually dissolved, so the solid SEI film-forming additive can be dissolved. The silicon-containing lithium ion battery has the advantages of high energy density, long cycle life, good rate capability, high safety performance, difficulty in expansion and deformation and the like.

The present invention relates to silica particles for an electrode material, and the silica particles are characterized in that the silica particles comprise silicon monoxide particles having a general formula SiOx; and a carbon layer, wherein the silicon monoxide particles are bonded by the carbon layer, and the silicon monoxide particles bonded by the carbon layer are coated by the carbon layer.The silica particles are compact, narrow in particle size distribution and small in specific surface area, and have the advantages of high capacity, high coulombic efficiency, low expansion, high cycle retention rate and the like.

The invention relates to a water-based conductive binder for a lithium ion battery and a preparation method of the water-based conductive binder, and the water-based conductive binder comprises the following components in parts by weight: 10-30 parts of a basic binder, 90-120 parts of a functional binder, 2-10 parts of an intrinsic conductive polymer, 2-20 parts of modified carbon nanotubes, 1000 parts of deionized water and 0.7-4.1 parts of an auxiliary agent. The preparation method is simple, the steps are easy to operate, the prepared water-based conductive adhesive has relatively high conductivity, a pole piece of the water-based conductive adhesive is high in peel strength, good in adhesive force and low in dosage, lithium ions can be easily embedded/embedded out, the performance of an active material is fully played, the internal resistance value of a battery is smaller, the gram capacity of a positive electrode is better played, and in a cycle, the capacity loss is less, and the cycle retention rate is higher.

The invention discloses a preparation method of a porosity controllable graphene modified silicon-carbon composite material. The preparation method comprises the following specific manufacturing steps: step one, preparing a pre-dispersed coarse silica powder sizing agent: firstly adding a dispersing agent and an addition agent into a solvent, stirring for complete dissolution, then adding high-purity metal silica powder with the particle diameter of 1 to 10 microns, and then stirring for uniform dispersion to obtain the coarse silica powder sizing agent; step two, preparing a nano-scale silicon sizing agent: adding the coarse silica powder sizing agent obtained in the step one into a dispersion tank, introducing protective gas into the dispersion tank, and adding a ball-milling medium intoa ball-milling tank according to the ratio of a grinding medium to a material being (200 to 20): 1; step three, preparing a nanometer silica powder; step four, preparing a graphene modified nanometersilicon composite sizing agent; and step five, preparing the graphene modified silicon-carbon composite material used for an energy storage material. The graphene modified nanometer silicon preparedby the method is controllable in porosity, and has the advantages of high mechanical strength, low specific surface area, high conductivity, high initial efficiency and high circulation retention rate.

The invention belongs to the technical field of preparation of cathode materials for lithium ion batteries, in particular to a core-shell ternary cathode material mLi [NibCocMnd] O2. NLi1 + e [NifCogMnh] 1 prepared by a low-temperature self-propagation method. EO2 (m+n=1, ne=a, mb+n (1-E) f=x (1-A), mc+n (1-E) g=y (1-A), md+n (1-E) h=z (1-A), 0.1 < = b <= 0. 5, 0.6 <= f <= 0. 9, 0 <= e <= 0. 4).At first, a high-nickel or lithium-rich core is prepare, and then a core-shell structure ternary cathode material is prepared as that core, and finally, the nano-and micro-scale core-shell ternary cathode material is obtain by high-temperature calcination. If the multilayer core-shell structure material is prepared, the shell is prepared repeatedly according to the actual design ratio. With the high stability ternary cathode material of low nickel as the shell, the core of high nickel or lithium-rich system which has many defects but high capacity is coated. Through the design of the structureand batch preparation, the obtained material will play a better role in the high capacity of the core and the stability of the shell. The preparation method is simple, rapid, low energy consumption,and does not need additional doping coating to increase the cost of capacity loss and other problems, so it is a practical and industrialized application method.

The invention provides a pole piece and a lithium ion battery. The pole piece comprises a current collector, a first active layer and a second active layer, wherein the first active layer and the second active layer are sequentially stacked on the surface of the current collector; the first active layer is provided with a first groove, the second active layer is provided with a second groove, and the vertical projection of the second groove on the current collector covers the vertical projection of the first groove on the current collector; and the tab is arranged at the first groove and is electrically connected with the current collector. According to the pole piece provided by the invention, the charging risk of the tab connection position is effectively improved, and the cycle retention rate of the lithium ion battery is improved under the condition of keeping high-rate charging.

The invention provides a metal lithium battery negative electrode, a preparation method thereof and a lithium secondary battery. The negative electrode provided by the invention can improve the cycle performance of the battery under the condition of high capacity density. A specific silane coupling agent and cyanoacrylate are subjected to transesterification to form a transesterification product, the surface of a negative electrode foil is coated with the transesterification product, and after coating, an anionic polymerization reaction is initiated by Li or a small amount of water in air, so that the transesterification product forms a spatial cross-linked network polymer; the cross-linked network polymer coating can effectively promote lithium ion penetration and induce lithium ions to deposit on the surface of the negative electrode foil, has good compatibility with the negative electrode foil, and can inhibit growth of lithium dendrites; the cross-linked network polymer coating is insoluble in electrolyte, so that side reaction between the electrolyte and metal lithium can be well inhibited; the cycle performance of the battery can be effectively improved through the effects in multiple aspects.

The invention discloses a negative electrode composite lithium-supplemented material for a lithium ion battery. The lithium supplemented-material comprises a compound comprising graphene and metal lithium, the mass ratio of the graphene and metal lithium being 1:(0.7-3.5); the graphene is a spun fibrous carrier; the metal lithium is uniformly distributed in the carrier and on the surface of the carrier; and the metal lithium distributed on the surface of the carrier is coated with a carbon layer. According to the lithium-supplemented material of the invention, an electrostatic spinning technology is adopted to realize the lithium supplementation of the negative electrode material; the fibrous graphene is used as the carrier, so that most of lithium is coated with the fibers; and the lithium supplementation can be continuously realized during the cycle process of the battery so as to improve the cycle retention rate of the battery. The obtained negative electrode composite lithium-supplemented material for the lithium ion battery has stable performance and high safety. With the negative electrode composite lithium-supplemented material for the lithium ion battery, uniform lithium supplementation is realized, the first efficiency and energy density of the lithium ion battery can be improved, and the long cycle performance of the lithium ion battery can be ensured.

The invention relates to a negative electrode active material for a battery. The negative electrode active material comprises the negative electrode active material particles, and the negative electrode active material particles contain a silica compound and comprise a lithium element, the doped metal M1 and the doped metal M2, wherein the metal M1 comprises one or more of titanium, magnesium, zirconium, zinc, aluminum, yttrium and calcium, the metal M1 comprises one or more of copper, nickel, iron, manganese, cobalt and chromium, the metal M2 comprises one or more of copper, nickel, iron, manganese, cobalt and chromium, and the metal M1 and the metal M2 account for 0.01-25 wt%, preferably 0.05-15 wt%, more preferably 0.1-10 wt% and more preferably 0.1-5 wt% of the content of the negativeelectrode active material. The battery prepared from the negative electrode active material has the advantages of high capacity, high coulombic efficiency, long cycle life and high water resistance.

The invention provides a metal lithium battery negative electrode, a preparation method thereof and a lithium secondary battery. The negative electrode provided by the invention can improve the cycle performance of the battery under the condition of high capacity density. Cyclodextrin substances and cyanoacrylate are subjected to transesterification to form a transesterification product, the surface of a negative electrode foil is coated with the transesterification product, and after coating, an anionic polymerization reaction is initiated by Li or a small amount of water in air, so that the transesterification product forms a spatial cross-linked network polymer; the cross-linked network polymer coating can effectively promote lithium ion penetration and induce lithium ions to deposit on the surface of the negative electrode foil, has good compatibility with the negative electrode foil, and can inhibit growth of lithium dendrites; the cross-linked network polymer coating is insoluble in electrolyte, so that side reaction between the electrolyte and metal lithium can be well inhibited; the cycle performance of the battery can be effectively improved through the effects in multiple aspects.

The invention discloses a quick-charging negative electrode material production process and device. The device comprises a bucket elevator, a stock bin, a melting tank, a pressurizing tower, a distillation tower, a crusher, a screening machine and a high-temperature carbonization furnace, wherein the bucket elevator is connected with the stock bin, the stock bin feeds materials to the melting tankthrough the screw feeder, the melting tank is connected with the pressurizing tower, a light phase extraction opening of the pressurizing tower is connected with the distillation tower, a coke outletof the pressurizing tower feeds materials to the crusher, the crusher feeds materials to the screening machine, and the screening machine feeds materials to the high-temperature carbonization furnace. According to the invention, different asphalt raw materials are coarsely crushed or directly melted, then enter the pressurizing tower for coking and are crushed and screened after coke discharging,and then the treated raw materials enter the high-temperature carbonization furnace for carbonization to obtain the negative electrode material with excellent electrochemical performance and stable material structure. The high-capacity quick-charging negative electrode material prepared by the invention is high in battery safety performance, high in capacity, good in rate capability, excellent incycle performance and outstanding in anti-attenuation capability, and is an excellent raw material for lithium ion and sodium ion batteries and quick-charging battery equipment.

The invention provides a positive pole piece modified by an electro-polymerization polymer film and a preparation method of an all-solid-state battery of the positive pole piece. The surface of the positive pole piece is modified with a layer of electro-polymerization polymer film by adopting an electro-polymerization method, the electro-polymerization polymer film prepared by the method is internally doped with electrolyte, the ionic conductivity is high, and the polymer film has a certain respiration effect, so that stress generated when a positive pole material is in contact with solid electrolyte can be relieved, and an interface is stable; and the advantages of the organic liquid electrolyte and the solid electrolyte are integrated, and the cycle performance of the solid-state battery prepared by the method is excellent.

According to the positive electrode material coated with the co-embedded thin film, the preparation method and the lithium ion battery, the co-embedded thin film is deposited on the surface of the positive electrode material through an atomic layer deposition method, so that the positive electrode material coated with the co-embedded thin film is obtained. The co-embedded thin film comprises an amorphous oxide layer of phosphorus and an amorphous oxide layer of titanium. By adopting the atomic layer deposition method, the precise regulation and control of the element content and proportion can be realized, the cost is low, the coating period is short, and the PO bond in the obtained co-embedded film with the specific element proportion and content can prevent the material structure collapse caused by material deoxidation; and the amorphous oxide layer of phosphorus and residual lithium of the positive electrode material can form fast ion conductor lithium phosphate, so that the interface impedance is reduced. The amorphous oxide layer of titanium has the effect of blocking electrolyte erosion. Therefore, the positive electrode material coated with the co-embedded film and the lithium ion battery assembled by the positive electrode material have relatively high capacity and cycle performance.